That brings me another question - when do the DK trinkets get replaced, and by what, if you're a tank ?

My DK is 73, I have maybe 6 northrend trinket in my bags (ilevel 138-146) and I can't for the heck of me tell if they are better for a tank than those default dodging proc, etc... we get out of starting area - can someone advice which are ?
(I have rating busters but the stats/proc aren't covered or overlap/compare - only the ilevel makes me think I should swap them,....)